Why are there not more Connies left? I don't know, but I have a theory, The Connie, like all Lougheeds was probably more expensive to begin with because it was much more complicated than its competition. This fact led to fewer being produced, and also led to much higher maintenance costs. It's pretty easy to understand that a complicated airframe and systems would be retired early.
Mr. Douglas' products on the other hand tend to be stone simple. As long as maintenance knows how to properly rig all the cables, a Douglas will last forever.
Here's a trivia question, Why did the Army Air Corps not utilize more P38s in WWII? It had great range, as proven by Lucky Lindy himself. Ask Yamamatos ghost. It was a great gunnery platform, Bong and Maguire both flew Lightnings. It was fast, decently manueverable and could get you home after suffering battle damage. Yet it wasn't as popular as other fighters. Why.
regards,
enigma